The program is designed to meet future requirements for biological test systems used in biomedical research. Since its inception in the early 1970's, some 75 new model systems have been developed utilizing the internal resources of the National Institutes of Health Genetics Resource (NIHGR). These include model systems for immunology, infectious diseases, parasitology, cancer, immune complex diseases, behavior, alcoholism, metabolic diseases to include diabetes mellitus, and cardiovascular diseases to include hypertension. The majority of the projects are collaborative in that they involve a close working relationship with the clinical investigator.